Rotary valves are useful in analytical laboratories and instrumentation for directing fluid flows to system components such as columns, loops, filters, detectors, and the like, and for switching between different components as well as different fluid sources. Rotary valves can thus be used to select and switch between components for such purposes as sample injection, sample stream selection, fluid redirection, fraction collection, solvent or buffer selection, and selections between different chromatography columns. The typical rotary valve has a stator and a rotor, with internal channels, usually in the form of grooves (elongated recesses) in the surface of either the stator or the rotor, most often the rotor, that bridge selected pairs of ports in the valve depending on the position of the rotor. In the typical rotary valve supplying a flow-through system component such as an analytical column, an internal channel in the valve will form a bridge between an inlet port on the valve and an inlet port to the flow-through component, while another internal channel in the valve will form a bridge between an outlet port from the same flow-through component and an outlet port on the valve. The internal channels typically contain a certain amount of dead volume, defined herein as a region of an internal channel through which fluid does not flow but is instead stagnant, while fluid is flowing elsewhere through the valve. A valve with dead volume must be cleaned periodically, and even with cleaning, the dead volume poses a risk of contamination of one fluid or sample with another when the valve position is switched. Aside from dead volume, the distance that the fluids travel through the internal channels can affect the efficiency of the component to which the fluids are directed. When the valve is utilized on chromatographic systems, for example, the additional travel distance through the internal channels of the valve can result in band broadening, reducing the precision with which solutes are detected and quantified. Certain rotary valves are also designed to provide the user with a choice between forward and reverse flow directions through a flow-through component. This complicates the valve design and in certain cases requires rotation of the valve by 180 degrees, raising the possibility of user error when the valve is rotated too far or not far enough, and the possibility of contamination when the valve must be rotated past one or more positions to reach the desired position.